6gt

[PatrickChewing]

Here is a little more powder/velocity info for folks.

Alpha brass (1x fired, no shoulder bump)
CCI BR4
Bart's 105 Gungnir
30 inch 8 twist Blake barrel

VARGET
33.2 - 2960
33.5 - 2972
33.8 - 2995
34.1 - 3003
34.4 - 3024
34.7 - 3051
35.0 - 3074
35.3 - 3092
35.6 - 3119
35.9 - 3136


H4350
36.5 - 2975
36.7 - 2974
36.9 - 2982
37.1 - 3001
37.3 - 3016
37.5 - 3023
37.7 - 3040
37.9 - 3053
38.1 - 3072
38.3 - 3091
Hope this helps!

 

[Turbwhistle]

Hey guys, i am building a 6gt bolt gun and was wondering what powder you’d start with out of bl-c(2), 4895, xbr 8208?

I have br-4 and 450 primers, alpha brass, and 108 bergers, i also have some Varget but not much. I been keeping an eye of for h350 but haven’t been able to get some yet.

 

[MilSpecOkie]

Hey guys, i am building a 6gt bolt gun and was wondering what powder you’d start with out of bl-c(2), 4895, xbr 8208?

I have br-4 and 450 primers, alpha brass, and 108 bergers, i also have some Varget but not much. I been keeping an eye of for h350 but haven’t been able to get some yet.

Any Varget class or H4350 class will work in the GT. Look for 4166, 4451, Staball, CFE223, RL15, 15.5, 16, 17 Whatever VV equivalents are and so on.

 

[Jefe's Dope]

I'd break in 36.5gr of H4350 with Alpha brass. One of the nice things about 6GT is there's pretty much no reamer variations. I'll wager you final charge weight will be around 36.7gr going 2900fps using Alpha brass.

Well there you go. I did five round strings starting at 35.0 going .2 each string except when I got to 36.4 I went to 36.5 then 36.6. They all did pretty good except 35.0 and 36.6.

Of course it was the worst group of the bunch. I just loaded 50 rounds at 36.5 and varying seating depths from .001 to .005 at .001 increments. But honestly, even the bad ones were probably better than most of my 6.5CM loads.

Keep coming with the advice because I can't take credit for this. Thanks for the hint.

 

[Dooby]

Has anyone tried Reloader 23? Thinking about giving this a try.

 

[Cascade Hemi]

Well there you go. I did five round strings starting at 35.0 going .2 each string except when I got to 36.4 I went to 36.5 then 36.6. They all did pretty good except 35.0 and 36.6.

View attachment 7817905

Of course it was the worst group of the bunch. I just loaded 50 rounds at 36.5 and varying seating depths from .001 to .005 at .001 increments. But honestly, even the bad ones were probably better than most of my 6.5CM loads.

Keep coming with the advice because I can't take credit for this. Thanks for the hint.

I'm using berger 109Hyb so my results are probably going to be different but most user loads I've seen posted are .030 to .050 off the lands.

 

[Jefe's Dope]

I'm using berger 109Hyb so my results are probably going to be different but most user loads I've seen posted are .030 to .050 off the lands.

I have those but I'm running the 108 BT right now.

 

[John Glidewell]

I have those but I'm running the 108 BT right now.

I am running 108s too. They did very well at .040 to .060 off lands.

 

[Darkside-Six]

My experience with the 109 hybrids across 3 barrels was .060 - .080 is where the sweet spot is. They’re not real jump sensitive but that’s is where they really tightened up for me.

 

[4O6shootist]

I have those but I'm running the 108 BT right now.

108bt ran very well 10 and 20 off in a prior barrel, like stupid good. 1.5" 10 shot groups at 500y. Was running rl16 @ 2940fps.

 

[Dooby]

It would probably be okay if you're okay with a slower speed. I like it for slow 6 Creed. The kernels are in all different shapes and lengths tho. Can be troublesome running through an auto Trickler.

Yea, trying to get slower velocity. I have one bbl that is just really fast. Same load on my other bbls and it's about 100-120fps faster.

I primarily use H4350. But seems like it needs good case fill for lower SD/ES. I have RL23 for use with my 6.5PRC (Barnes 127LRX) and may give this a try.

 

[4O6shootist]

Same base to ogive seating depth I've been running(-40) with 109s for 700 rounds. Barrel has just over 1400 on it. H4350 36.5(warm temps), 36.6(med temps, 36.7(cold temps) keeps speeds right at 2900. This was the cold weather ammo shot at 50° today, avg velocity was 2912 with es of 20 over 25 rounds fired. Same ammo shot 1.5" at 400y but didn't feel like hiking back up the snowy hill to fetch target. 50° and snow on the ground with swirly winds had pretty heavy mirrage, so groups may have been better in ideal conditions. Barrel is a BB steel bartlein 7.5tw 237 bore 28" hvy varm. This is what a person looks for in a prs load, super stable over the course of 700 rounds fired. I'm unsure of throat erosion as this point as I haven't checked since it just keep shooting. I just adjust the charge weight by 0.1 for different seasons as I'm not in a powder node, but the speed node of 2880-2910 held excellent vertical at 500y upon initial ladder. Last fall this velocity printed 4.7" group at 870y. All shooting is from a bipod and rear bag field conditions, no benchrest bs.

 

[Jefe's Dope]

108bt ran very well 10 and 20 off in a prior barrel, like stupid good. 1.5" 10 shot groups at 500y. Was running rl16 @ 2940fps.

It liked .10 today. But I got better SDs/EDs at .50 and was just a little tighter. But after reading above, it looks like I need to push a little farther to see.

I had a roll going until the 5th round. It read an SD of 0.0 right before shot 5. My panties got a little moist and I think it slowed down shot 5.

 

[ucsfl05]

Anyone used RL15.5 for the 6gt? My varget is running low and will need to experiment. Any help much appreciated!

 

[John Glidewell]

Yes. Posted load data here a few days ago from Berger. Although I do not agree with their data, it is Very conservative. I have run 2 different rifles now, 3 barrels and a bunch of different bullets. I also use QuickLoad and they all topped out around 35 grains with a 62k max pressure. I am running 33.7 with 108BTs and my Wife is running 33.6 with 105 hybrids. Both at .040 off lands, 2938 and 2957 respectively.

 

[John Glidewell]

Also, I think I figured out why Bergers data is off. I used RL16 and adjusted burn rate, as the 15.5 and 16 are both temp stable with 2% or less of nitroglycerin, what they call near single base. RL15 is a much higher nitroglycerin, up to a possible 40% according to MSDS. I switched my profile to RL15 and adjusted burn rate to match velocity and the max was very close to Berger numbers. I feel our data is good as we actually shot to pressure. We did that because we got the first 2 cases of RL15.5 and there was NO load data available. We shot Alpha OCD and Hornady. 15.5 is a great powder the GT.

 

[Royc61]

what barrel life are guys getting now that's it been out a bit?

My buddy said his took a dump at ~1000-1200rds he was pretty bummed.

another said he pulled his at 1800. but only because it was a good time to switch to his second GT barrel. he said it was still shooting well

I have a hawk hill with 2800 rounds on and it’s still going strong ,disclaimer I end up at 2850 with almost all my bullets 109s 105s Berger and 108 eldm

 

[4O6shootist]

I have a hawk hill with 2800 rounds on and it’s still going strong ,disclaimer I end up at 2850 with almost all my bullets 109s 105s Berger and 108 eldm

Is that a prs rig? 2800 is up there for a gt. Ive ran mine pretty hard as its a match rig, but at 2900 from a 28" with 4350 in a mod400 BB steel bartlein, hoping it should live a long life. Shooting matches in summer heat, the barrels are hot all day long.

 

[Darkside-Six]

Is that a prs rig? 2800 is up there for a gt. Ive ran mine pretty hard as its a match rig, but at 2900 from a 28" with 4350 in a mod400 BB steel bartlein, hoping it should live a long life. Shooting matches in summer heat, the barrels are hot all day long.

I’ve gotten 3400 on my 26” Bartlein when I pulled it. Was still shooting fine. Did it more so for piece of mind.

 

[4O6shootist]

I’ve gotten 3400 on my 26” Bartlein when I pulled it. Was still shooting fine. Did it more so for piece of mind.

Thats great to hear. There's hardly any fire cracking in this thing at 1400, maybe 50k of the freebore shows wear, but nothing else. I measured lands prior to barrel install, then pulled barrel and measured again at 700 rounds and it only moved 005. I was pretty impressed.

 

[4O6shootist]

He didn't say anything about firecracking or throat erosion. He just said he left it on the gun for 3400rds

I understand that, but for a barrel to go 3400 and still be shooting good, which is 1k more than most gt's I've heard of, the bb steel must indeed hold up quite a bit better. My buddy has pulled his last 3 dasher proof prefits just shy of 2k due to flyers becoming a norm. He never ran them that hard either. I think the varget/short neck dasher combo is not barrel friendly. I guess the throat life comment was just me thinking out loud. I think the jury is still out on the harder alloy from bartlein, but the more of em that guys kill, the more data we have.

 

[Royc61]

Is that a prs rig? 2800 is up there for a gt. Ive ran mine pretty hard as its a match rig, but at 2900 from a 28" with 4350 in a mod400 BB steel bartlein, hoping it should live a long life. Shooting matches in summer heat, the barrels are hot all day long.

Yes it’s for prs everyone keeps saying it should be done , my next match is in a week and half and I’m going to put my other barrel on.

 

[Royc61]

Exactly.

I'm actually agreeing with you. Be cautious of claims of barrel life by people without a lot of data. Some people just leave a barrel on for a long time. Oh, it was shooting, "Good". Pretty subjective metric.

By good I mean it still shoots the same half inch at the same speed it shot after I broke it in .

 

[Royc61]

We weren't talking about your post

 

[Darkside-Six]

Exactly.

I'm actually agreeing with you. Be cautious of claims of barrel life by people without a lot of data. Some people just leave a barrel on for a long time. Oh, it was shooting, "Good". Pretty subjective metric.

Well feel free to scroll way back through the thread where I’ve spoken about it in more depth. No I didn’t measure fire cracking or any of that shit. But it still held the same velocity (2850) and still held right groups. Shit a few matches with it when it hit 3k and had no issues. Not trying to claim anything other than what I said. I pulled it at 3400. Could just be an anomaly, who knows. Just put it out there for people that think they need to pull their barrel at 2k. I shoot with several others that made it to 2500+ as well.

 

[ghostrider_OneOne]

Well feel free to scroll way back through the thread where I’ve spoken about it in more depth. No I didn’t measure fire cracking or any of that shit. But it still held the same velocity (2850) and still held right groups. Shit a few matches with it when it hit 3k and had no issues. Not trying to claim anything other than what I said. I pulled it at 3400. Could just be an anomaly, who knows. Just put it out there for people that think they need to pull their barrel at 2k. I shoot with several others that made it to 2500+ as well.

I've posted this before and everyone ignored it will do again in spirit of alternative loads that work well.
4166 32.4 105bthp hornady 2830fps avg
5 shot groups 1/4 inch
ES 8. SD 3
Last week 50shot sample size 2831fps avg Es21 Sd6.5
If were to remove 4 "flyers" Es down to 13
I'm sure many have had good results with various combinations but have yet to hear this type of consistency over a 50 shot sample size.
Rifle: GAP PPR
Horn brass, S&B primers, Horn brass, 1.715 trim, FL resize .002 bump, annealed, 3rd sizing
COAL 2.500
If you're having a difficult time finding top end components, like me, or don't want spend your entire savings. There is hope! All these were components were cheap and relatively easy to find.
Not super sexy but rock solid consistent.


"Rangers lead the way"

 

[MDof2]

I’ve gotten 3400 on my 26” Bartlein when I pulled it. Was still shooting fine. Did it more so for piece of mind.

Mod400 steel?

 

[Darkside-Six]

Mod400 steel?

No. Regular. Wired thing is it was even a pre fit from Area 419.

 

[Niles Coyote]

Mod400 steel?

I can confirm his round count too...


**updated after reviewing my log** My regular stainless Bartlein has 2926 rounds fired now. The throat has grown a bit but still shooting good. From un-fired/new to now my throat has moved .090", this measurement is taken with the same bullet throughout the barrels life. This averages .003" of growth for every 100 rounds fired. The rifle saw 34.3 gr of varget for the first 700 rounds then I embraced the slower is better mentality and moved to 32.6 grain of varget, in hornady brass with 109 Berger hybrid's. This yields 2845 as of last check, which is 106fps slower than the hotter load and based on averages taken.

When I reworked my load at around the 700 rounds fired mark I was jumping .060" and I've maintained the same setting on my seating die since then, which puts my current jump at .111"

Now with all that said I have started using 108 eld's in this barrel now due to Berger availability and will continue those until the barrel stops shooting well.

Current targets from the past three months. 10 shot group on the 700y target.

 

[DeathBeforeDismount]

I'd break in 36.5gr of H4350 with Alpha brass. One of the nice things about 6GT is there's pretty much no reamer variations. I'll wager you final charge weight will be around 36.7gr going 2900fps using Alpha brass.

I run 36.7 H4350 alpha brass 450/BR4 and was getting 2940 on virgin and get 2967 on once/twice fired. running 109s as well at 2.555"

I wonder if case fill matters? having a higher % of case fill resulting in less SD/ES. This would lean towards hotter loads shooting better.

I get about a 5-7SD depending on the day with the same load, same gun ect.

 

[Juggerxxx]

Very close to 2800 rounds down a standard SS Bartlein barrel that has been used 95% of the time at PRS matches and it’s still shooting great and hasn’t lost velocity. It only comes out for 1 day matches anymore. That shooting 109s at 2860fps with 35.5gr of H4350. I have 2200 rounds down another barrel and it too is still shooting well. Keeping my fingers crossed it holds on this weekend in Oklahoma.

 

[Roksliding]

I personally had a spectacular 112 mb failure at the AZ 2 day match. Had a roughly 30% explosion rate from the jackets separating. I'm not sure if it was the heat (112°), or what but 2850 fps and a 7.5 twist should not have led to them poofing. I could have had a fucked up lot I don't know.

I’ve had similar issues this last weekend, though closer to 15%. They would just come apart in flight, people at the line on their glass said they could see vapor trail(s) going left to right randomly….

I cannot say enough bad things about Barnes Match Burner 112. Absolute trash

 

[SD Carpenter]

I’ve had similar issues this last weekend, though closer to 15%. They would just come apart in flight, people at the line on their glass said they could see vapor trail(s) going left to right randomly….

I cannot say enough bad things about Barnes Match Burner 112. Absolute trash

I 100% agree. They are extremely cheap for a reason. The integrity of their bullet construction really needs to be set higher. That said, when they work, their bc is on point.

 

[Bolt Thrower]

Temporarily pulled barrel (26" Benchmark VCC) at just under 1,500 rounds. It still shoots great groups at 100 yards, but will only hold ES<40 when the barrel is clean and fouls up quickly.

Data for rounds 15 through 30 on a new barrel (26" Bartlein M24, Stuteville Impact Prefit, 1:7.5" twist) with new brass:

Berger 105 gr Hybrid
CCI 450
Alpha OCD Brass (virgin, mandrel/chamfer only)
+/-0.050" jump
33.0 gr Varget
Ave MV: 2,811
ES: 23
SD: 7
Groups were 0.3" to 0.5" @ 100 yards

 

[Gtscotty]

My StaBall load that I thought I finally had sorted out went wonky on me, so I think I'm done messing with it in my GT, works fine in the 6.5.

Anyway, I have a fair amount of RL16, and 36.8gr looks alright under a 112gr MB. I did just snag some 109gr Hybrids, and I'm curious if anyone has a pet load with RL16 I might use to figure out a good starting point?

From reading back through the thread, it's pretty clear that 109gr loaded 0.060 off over 36gr to 36.5gr H4350 is pretty popular, seems like RL16 should work great as well.

 

[Darkside-Six]

My StaBall load that I thought I finally had sorted out went wonky on me, so I think I'm done messing with it in my GT, works fine in the 6.5.

Anyway, I have a fair amount of RL16, and 36.8gr looks alright under a 112gr MB. I did just snag some 109gr Hybrids, and I'm curious if anyone has a pet load with RL16 I might use to figure out a good starting point?

From reading back through the thread, it's pretty clear that 109gr loaded 0.060 off over 36gr to 36.5gr H4350 is pretty popular, seems like RL16 should work great as well.

Yeah that’s a good starting point. I didn’t run a test with 109’s but I did with the 110 A-tips and 36.3 was 2860ish. My Varget loads with A-tips is the same with 109’s so I would venture a Guess that you’ll be fine right in that area.

 

[vwpilot]

I have been using RL16 as a break in load for my GT as I only had a pound of it so figured I’d use it. Now I wish I had more.

35.7 grains with a 108 ELDm has been shooting very well for me.

 

[bfk4lyfe]

(un)official beer of 6GT?

 

[Hutch_WV]

I 100% agree. They are extremely cheap for a reason. The integrity of their bullet construction really needs to be set higher. That said, when they work, their bc is on point.

I have had great luck with them. 26” Bartlein 7twist.

 

[Niles Coyote]

I can confirm his round count too...


**updated after reviewing my log** My regular stainless Bartlein has 2926 rounds fired now. The throat has grown a bit but still shooting good. From un-fired/new to now my throat has moved .090", this measurement is taken with the same bullet throughout the barrels life. This averages .003" of growth for every 100 rounds fired. The rifle saw 34.3 gr of varget for the first 700 rounds then I embraced the slower is better mentality and moved to 32.6 grain of varget, in hornady brass with 109 Berger hybrid's. This yields 2845 as of last check, which is 106fps slower than the hotter load and based on averages taken.

When I reworked my load at around the 700 rounds fired mark I was jumping .060" and I've maintained the same setting on my seating die since then, which puts my current jump at .111"

Now with all that said I have started using 108 eld's in this barrel now due to Berger availability and will continue those until the barrel stops shooting well.

Current targets from the past three months.View attachment 7821774View attachment 7821775View attachment 7821776

Updates added to my post above.

 

[MDof2]

Updates added to my post above.

Good info.
Dumb luck had me in the right place at the right time and I was able to grab a Mod400 stick to have on the shelf for when I run through the current Bartlein barrel I have on my GT now. Current barrel shoots wicked now so if the next does the same, I'm all kinds of happy with 3000+ rounds for barrel life. I'm +/-1000 rounds on my current, so will probably be a next winter spin up if I can sneak though this season with this barrel.

 

[4O6shootist]

Im at 500 rounds on my 22gt, 35.8gr H4350 90s @ 3100, and 1500 on the mod400 6gt, 36.6gr H4350 109s at 2900, just cleaned both last night, they don't look much different, the 6 has slightly more dragon scale in the beginning of freebore, and a we bit more fire cracking.

 

[BigB1]

Hi, Looking at a new 6GT build at the moment but availability of barrels and components etc down here in Australia is not great.
The barrels I have available are Bartlein 5r in 7 or 7.75 twist. Projectiles would be 107 Sierra matchkings and I have both Varget and H4350 to play with.
Question is will the 7 twist barrel work ok with 107 SMK's?

 

[Niles Coyote]

Question is will the 7 twist barrel work ok with 107 SMK's?

Welcome to the hide. Yes, a 1-7 will work just fine and be desired for Sierra's 110 should you want to try that one.

 

[Roksliding]

What size bushing are you guys using with the Hornady brass?? .002 preferably..

Thanks

 

[Darkside-Six]

What size bushing are you guys using with the Hornady brass?? .002 preferably..

Thanks

I use .266. Which gives me 0.002 with the 109 and 105 hybrids.

 

[Roksliding]

I use .266. Which gives me 0.002 with the 109 and 105 hybrids.

Appreciate you. Thanks

 

[4O6shootist]

267 redding non-coated bushing gives me 002 w/ alpha.

 

[Gtscotty]

I was using .266, with Hornady brass, sometimes it felt like the mandrel was so lightly touching the neck I wasn't sure if I was really getting consistent tension. I picked up a .265, and there's definitely more mandrel effort, but performance seems the same, so the .266 was probably fine.

On the mag topic, I need to pick up an accurate mag to try, and was curious if folks who have good luck with them are using the bindered or binder-less versions? Normally I'd go binder-less for most chamberings to have the option to load long, but the GT obviously doesn't need it, and I wonder if the extra length might have an impact on feeding?

 

[4O6shootist]

I was using .266, with Hornady brass, sometimes it felt like the mandrel was so lightly touching the neck I wasn't sure if I was really getting consistent tension. I picked up a .265, and there's definitely more mandrel effort, but performance seems the same, so the .266 was probably fine.

On the mag topic, I need to pick up an accurate mag to try, and was curious if folks who have good luck with them are using the bindered or binder-less versions? Normally I'd go binder-less for most chamberings to have the option to load long, but the GT obviously doesn't need it, and I wonder if the extra length might have an impact on feeding?

Ive ran arc, pmag, and accurate non binder without any problems. My biggest feed issues was with mdt non binder, I just tossed em back in the parts box. Those mags have only done okay with the 25cm. And still needed tuning.